net.sf.saxon.pattern

## Class EmptySequenceTest

- java.lang.Object
- - net.sf.saxon.pattern.NodeTest
  - - net.sf.saxon.pattern.EmptySequenceTest

- All Implemented Interfaces:
    Serializable, ItemType

      public final class EmptySequenceTest
      extends NodeTest

  NodeTest is an interface that enables a test of whether a node has a particular name and type. An EmptySequenceTest matches no nodes or atomic values: it corresponds to the type empty-sequence().
  Author:
    Michael H. Kay
  See Also:
    Serialized Form

- - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `double` | `getDefaultPriority()` Determine the default priority of this node test when used on its own as a Pattern
    `static EmptySequenceTest` | `getInstance()` Get a NoNodeTest instance
    `int` | `getNodeKindMask()` Get a mask indicating which kinds of nodes this NodeTest can match.
    `ItemType` | `getPrimitiveItemType()` Get the primitive item type corresponding to this item type.
    `int` | `getPrimitiveType()` Get the basic kind of object that this ItemType matches: for a NodeTest, this is the kind of node, or Type.Node if it matches different kinds of nodes.
    `int` | `hashCode()` Returns a hash code value for the object.
    `boolean` | `matches(int nodeKind, NodeName name, int annotation)` Test whether this node test is satisfied by a given node.
    `boolean` | `matches(NodeInfo node)` Test whether this node test is satisfied by a given node.
    `boolean` | `matches(TinyTree tree, int nodeNr)` Test whether this node test is satisfied by a given node on a TinyTree.
    `boolean` | `matchesItem(Item item, boolean allowURIPromotion, Configuration config)` Test whether a given item conforms to this type
    `String` | `toString()`
    `void` | `visitNamedSchemaComponents(SchemaComponentVisitor visitor)` Visit all the schema components used in this ItemType definition

    - ### Methods inherited from class net.sf.saxon.pattern.NodeTest

      `getAtomizedItemType, getContentType, getFingerprint, getRequiredNodeNames, getSuperType, isAtomicType, isAtomizable, isNillable, isPlainType, matches`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Method Detail

    - #### getInstance

          public static EmptySequenceTest getInstance()

      Get a NoNodeTest instance

    - #### getPrimitiveType

          public final int getPrimitiveType()

      Description copied from class: `NodeTest`
      Get the basic kind of object that this ItemType matches: for a NodeTest, this is the kind of node, or Type.Node if it matches different kinds of nodes.
      Specified by:
        `getPrimitiveType` in interface `ItemType`
      Overrides:
        `getPrimitiveType` in class `NodeTest`
      Returns:
        the node kind matched by this node test

    - #### getPrimitiveItemType

          public ItemType getPrimitiveItemType()

      Get the primitive item type corresponding to this item type. For item(), this is Type.ITEM. For node(), it is Type.NODE. For specific node kinds, it is the value representing the node kind, for example Type.ELEMENT. For anyAtomicValue it is Type.ATOMIC_VALUE. For numeric it is Type.NUMBER. For other atomic types it is the primitive type as defined in XML Schema, except that INTEGER is considered to be a primitive type.
      Specified by:
        `getPrimitiveItemType` in interface `ItemType`
      Overrides:
        `getPrimitiveItemType` in class `NodeTest`
      Returns:
        the corresponding primitive type

    - #### matchesItem

          public boolean matchesItem(Item item,
                            boolean allowURIPromotion,
                            Configuration config)

      Test whether a given item conforms to this type
      Specified by:
        `matchesItem` in interface `ItemType`
      Overrides:
        `matchesItem` in class `NodeTest`
      Parameters:
        `item` - The item to be tested
        `allowURIPromotion` -
        `config` -
      Returns:
        true if the item is an instance of this type; false otherwise

    - #### matches

          public boolean matches(int nodeKind,
                        NodeName name,
                        int annotation)

      Test whether this node test is satisfied by a given node. This method is only fully supported for a subset of NodeTests, because it doesn't provide all the information needed to evaluate all node tests. In particular (a) it can't be used to evaluate a node test of the form element(N,T) or schema-element(E) where it is necessary to know whether the node is nilled, and (b) it can't be used to evaluate a node test of the form document-node(element(X)). This in practice means that it is used (a) to evaluate the simple node tests found in the XPath 1.0 subset used in XML Schema, and (b) to evaluate node tests where the node kind is known to be an attribute.
      Specified by:
        `matches` in class `NodeTest`
      Parameters:
        `nodeKind` - The kind of node to be matched
        `name` - identifies the expanded name of the node to be matched. The value should be null for a node with no name.
        `annotation` - The actual content type of the node
      Returns:
        true if the node matches this node tst

    - #### matches

          public boolean matches(TinyTree tree,
                        int nodeNr)

      Test whether this node test is satisfied by a given node on a TinyTree. The node must be a document, element, text, comment, or processing instruction node. This method is provided so that when navigating a TinyTree a node can be rejected without actually instantiating a NodeInfo object.
      Overrides:
        `matches` in class `NodeTest`
      Parameters:
        `tree` - the TinyTree containing the node
        `nodeNr` - the number of the node within the TinyTree
      Returns:
        true if the node matches the NodeTest, otherwise false

    - #### matches

          public boolean matches(NodeInfo node)

      Test whether this node test is satisfied by a given node. This alternative method is used in the case of nodes where calculating the fingerprint is expensive, for example DOM or JDOM nodes.
      Overrides:
        `matches` in class `NodeTest`
      Parameters:
        `node` - the node to be matched
      Returns:
        true if the node test is satisfied by the supplied node, false otherwise

    - #### getDefaultPriority

          public final double getDefaultPriority()

      Determine the default priority of this node test when used on its own as a Pattern
      Returns:
        the default priority

    - #### getNodeKindMask

          public int getNodeKindMask()

      Get a mask indicating which kinds of nodes this NodeTest can match. This is a combination of bits: 1<
      Overrides:
        `getNodeKindMask` in class `NodeTest`
      Returns:
        a combination of bits: 1<

    - #### visitNamedSchemaComponents

          public void visitNamedSchemaComponents(SchemaComponentVisitor visitor)
                                          throws XPathException

      Visit all the schema components used in this ItemType definition
      Specified by:
        `visitNamedSchemaComponents` in interface `ItemType`
      Overrides:
        `visitNamedSchemaComponents` in class `NodeTest`
      Parameters:
        `visitor` - the visitor class to be called when each component is visited
      Throws:
        `XPathException` - if an error occurs

    - #### toString

          public String toString()

      Overrides:
        `toString` in class `Object`

    - #### hashCode

          public int hashCode()

      Returns a hash code value for the object.
      Overrides:
        `hashCode` in class `Object`

Copyright (c) 2004-2013 Saxonica Limited. All rights reserved.